Flexible tubular structures



Dec. 22, 1964 w. P. BAzlNET, JR

FLEXIBLE TUBULAR STRUCTURES Filed Jan. 16, 1965 INVENTOR WILFRED I? BAZINET, JR.

ATTORNEY United States Patent O 3,162,214 FLEXEBLE TUEULAR STRUCURES Wilfred l. Bazlnct, Llr., Webster, Mass., assigner to American @ptical Company, Southbridge, Mass., a corporation of lvlassachusetts Filed lan. 16, 1963, Ser. No. 251,974 4 Claims. (1. 13d-120) This invention relates to tlexible tubular structures and particularly to a structure capable of being manipulated adjacent one of its ends for controlled ilexing thereof.

The invention contemplates the provision of a flexible tubular structure which may be controlled as to its extent and radius of curvature when iiexed and which is adapted to house optical viewing means and/or instruments for use in endoscopic examination or treatment. While the structure of the invention is particularly adapted for medical endoscopic devices, it has utility in other fields as a housing for tools, instruments or Viewing devices required to be extended around corners or into normally inaccessible places.

An object of the present invention is to provide a flexible tubular structure adapted to be manipulated'adjacent one of its ends for controlled flexing thereof.

. Another object is to provide for the housing of viewing devices, instruments or tools and for controlled manipulation thereof.

A further object is to provide a structure of the above character which is simple in construction, economical to manufacture and easily assembled or disassembled for vpurposes of cleaning and/or replacement of various elements thereof. A

To attain the aforesaid objects and others which may appear from the following description, in accordance with the principles of my invention, I provide a tubular structure including a continuous relatively thin walled tube formed of elastic material which is supported throughout its length by a series of rigid rings.

Two sets of rings are provided, one of which comprises a type having an outside diameter slightly larger than the normal or relaxed inside diameter of the elastic tube `and the other set cornprises a type having an inside diameter of approximately the same dimension as the outside diameter of rings of said first mentioned type.

Rings of the first mentioned type are placed internally of the elastic tube and spaced from one another by rings of the latter type which are positioned over the tube. Respective rings in the series thereof are brought into spaced adjacent end-to-end relation with each other along the length of the tube with the spacing therebetween o being approximately equal to or' slightly greater than the thickness of the elastic tube. Inner rings are each provided with one or more pairs of diametrically opposed openings extending longitudinally through their side walls.

Corresponding openings in respective inner rings are substantially coaxially aligned with each other throughout the length of the tubular structure. Wires or cables for manipulating the tubular structure are extended through the openings in the inner rings and are anchored at their one ends to the last of said inner rings adjacent the distal end or" Irhe structure. Opposite ends of the cablesextend outwardly of the proximal end of the structure to permit manipulation thereof. A pulling force applied to one cable of a diametrically opposed pair there-oiC will produce flexing or bending of the tubular structure in the plane defined by the pair of cables and the direction of bending will be toward the side adjacent the cable being e pulled.

As a result of the tube being elastic in nature, bending of the structure will take place at locations along its length between adjacent ends or" the respective inner and outer rings in the series thereof while the cross-section y BddZld Patented Dec. 22, 1964 of the structure will remain :substantially constant at all times so that a crimping eifect on articles supported therein will not be realized.

The extent of ilexing is determined by the amount of force exerted on the cable and, as it will become apparent hereinafter, the structure when tlexed will assume a circular shape.

The bending radius of the tubular structure and its general overall flexibility is determined by the lengths of respective rings used to support the tube. That is, rings of shorter axial dimension will permit bending about smaller radii of curvature and provide for increased ilexibility of the structure as a Whole. Longer rings Will limit bend-ing to larver radii of curvature and produce a more rigid overall structure.

The exibility and-bend radius of the tubular structure may be planned by selection of the lengths of rings used to support the elastic tube which will conform readily to substantially any degree of bending by stretching between respective adjacent ends of the inner and outer rings at one side of the structure and compressing between respective rings at the opposite side of the structure.

It is pointed out that the invention provides a tubular structure wherein the elastic tube, being continuous from end-to-end, forms a protective covering for instruments or the like intended to be extended thereinto.

The invention Will be more fully understood by reference to the following detailed description which is accornpanied by drawings in which FIG. 1 illustrates, in elevation, an embodiment of the present invention;

FIGURES 2 and 3 are enlarged perspective Views of supporting rings used in the construction of the embodiment shown lin FIG. l;

FIG. 4 illustrates, in enlarged form, a longitudinal cross-section of the improved flexible tubular structure of the invention; and

PIG. 5 is a view similar to FIG. 4 illustrating a modification of the invention.

Referring now to the drawings, there is shown in FIG. 1 a flexible tubular structure 10 constructed in accordance with the invention.

As shown in more detail in FIG. 4, structure 1t) comprises continuous elastic tube 12 which forms the side Wall of structure lll. Tube 12 is supported throughout its length by a series of rigid rings 14 and 16 which are tted thereto and positioned in adjacent end-to-end relation with each other.

Rings 14, being of one type, are provided with relatively thick side walls and are of an outside diameter somewhat larger than the normal or relaxed inside diameter of tube 12. Rings 16, being of another type, are provided with relatively thin side Walls of a thickness approximately equal to that of tube 12 and have an inside diameter approximately equal to the outside diameter of rings 14. Thus, the outer surface of the assembled structure is of substantially constant diameter except at the zones between rings. As it can be seen in FlGS. 2 and 4, rings 14 are each provided with diametrically opposed openings 18 extending longitudinally through their side walls. When rings 14 are positioned internally of tube 12 as shown in FIG. 4, corresponding openings 18 in respective rings 14 are coaxially aligned and wires or cables Ztl and ZZ are extended therethrough to provide means for llexingstructure 1t). Cables Zd and 22 may be in the form of Wires or structural cordage of natural or synthetic lamentary materials. e

One end of each of the cables 2t) and 22 is anchored to the particular ring 14 nearest the distal end of structure 10 (see FIG. 4). It the cables are in the form of stranded cords or the like, anchoring or their one ends may be accomplished simply by providing a knot at said ends which is larger than openings '18. Alternatively, direct or indirect-connection .ofthe ends of cables 20V and 22 to a" ring I4-may bemadebyswaging, cementing or .otherwise connecting beads 24V or the .like to cablesl 20 and 22 as illustrated in FIG. 4. Beads 24 may be cemented, welded tor otherwise -attachedtorin'g flzt itdesired. Wedges might -also'befused 'to securecables 20v-and, 02.2in openings 18.

In making the assembly of structure 10, a irst ring 14 Ehaving` cables :20 -and :22 extended throughits openings 18 4is iplaced internally of tube -1-2 Vadjacent-one ofits ends A.therebyr'causinjg -tube l12 tto yexpand and elastically grip first ring 14. `Cables 20 and 22 are extended fromfrst cables 20 'and ,22 might be .threadedrthrough openings 30 .and anchored .adjacent .the distall end of structure 10.

Operation vof this second set of cables would produce a iiexing'of the tubular'structure in a plane normal to the direction of iiexing illustrated in FIG. vl.

Y In the modification shoWnrin'FIrG. 5, rings of diierent axial lengths are .used in Vtheconstruction ofltubular struc- :ring `14 through tube 12 outwardly of its ropposite end and arin'g n1'6 isfslippedfover tube '.12 adjacent said opposite-Lend thereof. Thisring '16-is-then broughtinto .adjacent :end-toend frelation with [first-ring 1'4 with-a spacing beingprovidedtherebetween whichis approximately equal fto voronly"slightly greaterV thanthe thickness of tube '12. zIn this Way, tube i12-forms a.flexiblezconnecti'ony between adjacent rings 14 and 16 which permitsexing ofthenal Astructure f substantiallywithoutv alteration of its crosssectionalrsize -a'tfpoints between respective adjacent rings '1f4.and 116; rAisecon'd-ring 14 -is threaded onto cables 20 sand 22 andtted internally of'tube i12. Secondring 14 is Ythen moved into adjacent end-'to-end spaced relation `with .ring rlpipreviously applied. VCables 20 and 22 are held taut and areldisposedin thefplane of openings 18 in 'rstfring 14 ofthe 'assembly so lasto cause corresponding :openings =18 in second ring'14-to Vbecome yalignedv withl Jopeningsrin rstfring .14.4 AAzfsecond ring '16.is-thenifitted- IZbetWeen ringsl'4an'd 16 will stretch at the side of strucn ture 1G opposite to the cable having a'pulling"force/applied thereto andfbecome compressed lat .the side of. structure 10 MadjacentithefV cable shaving` .a pulling .force applied thereto. In FIG. l, cable 22 is illustrated as havingxatpu'lling force exerted thereon by*counterclockwise"rotation of'lever 26. :Lever .'26 is .shown for purposes f of .illustration j only and 'maybefreplaced'rbyfazpulley orithe likeor cables 20'and y:22 fmayf be: operated Without such .'devices Vvif' it is sov desired.

Y When-structure 10gis restrained throughout sectionA Y thereof as illustrated in FIG. 1, its free end section B iwill ex'orbendlindependently of section A infresponse Vtto .apulling force'applied to one'of vthe cables 420 or-22.

"ture 10'. Thus, sectionC of structure :10' longer rings-14 and 1'6, will-be less Iflexible and have a :shorter-radius of'zbend'than having ,the

longer radius of bend :than Ysection D.

By. the provisiono'f shorter rings-14jand 16 1n sectlon D; this section will b'ec'za'pableV of being exed about a section C, g fItis also illustratedin FIG. 5 that aexibletubular structurer'of'the type embodying thisyinvention may ybe :fitted to a lrigid .or-semirig1d"tube ,or casing 32 if it is' zdesired to provide-such 1a casingv `iend v:section which can '.be manipulated independently of y:casing :32.

ther-principles :set out *above might embody a ltube V12 with a iiexible terminal .A typical' tubular :structure constructed according to rforrned (of frubberfof the .type .usedfor conventional imedical'sleeving with rings 14 yand l16 formed of a rigid -plastic :such asrnylo'n.. Y l

The invention, however, is not limited to theusey of any fparticular fmaterials 1in `the yfabrication of the exible tubularstructure.l The VV.selection of .materials wouldbe made in accord-ance y.with theintended use ofthe exible tubularstructure- For .different applications it,might be Aminimumgradius ofxbendfRisA determined `by thevlengths 4of rings 'I4-rand 16. 'Rings l14.an"d 16 offshorter axial length will permittben'ding' about a 'shorter x radius :R and longer Irings 14f1an'd :.1'6 willflimit .bending vto' a longer .radius Thus, :it-can ibeseen 'thatca desiredjminimum Aradius ofbend `throughout apredetermined: lengthVV of struc-v turez10` canbeplanned-fatthetimestructure 119 is made up"by.prov1'd1ng -rings -14 :and 16 of .controlled vvlengths.

The amount of flexing. 'or-.bend which isfi'mparted tolstructuref101s rdetermined'by thetpull exerted on vcablef22.

Itshould'fbe'understoodthat withoutsection A ofy structure 1`0 being' restrained .as rshownz in FIG. 1, bending will take'place .throughout the entire klengthof structure 10 when azpulhngforce;is;;exerted oncable 22. y

Bending-of structure =10 inftheV direction-indicated byl dot-dashsoutline E28 icanbet-:eifected by rotating :lever "26 y yclockwise as viewed in FIG. 1 to apply af-pullingforce to cable 120. yI-t `is pointed sout'that, iffuniversal bending yof Ithe structure -10=is desired,rrings f14rnigl'1t be -provided with fa secondpair of diametrically opposed openings 30 Y =(see FIG; 2) 'disposed in aplaue normallto the-plane of openings 11'8. lthis wayfa second set v'of cables like Adesirable'.torformtube 1-2.of dierenttypes of natural or synthetic rubber or a woven elastic type sleeVing. Rings i1'4 and :16 'maybe formed yof :any rigidplastic -materlal for; metal.

iSince 'the *flexible tubular Vstructure -is adapted to a variety.of'uses,k.the ysizes :of its vvarious :parts would be determined accordingly.'` As' a gastroscope,for'example it jmight have Y. an outerq'diamet'er .of .approximately l. one

:centimeter-'for dess. For :other -purposessuch as in the 4machineitool tradefit might `-be laszmuchxas v.one or -more inches 2 in diameter. Y

From'theforegoing itv can be .seen fthat the .present in- "vention provides; a flexible-tubular structurehavinga .continuousf side wall forzthe .protection of tools, optical viewling systems, instruments :or v'other :forms :of equipment o which frni'ght -be housedtherein;Y :The structure may 'be .easily vassembled and `L disassembledfor purposes of cleanfin'g. or replacement vofspartszthereof and it `may. be Aformed to any desired length.rv

, (I claim:

1r-A exible 'tubular lstructureof .the 'character de- Ascribed'comprisingfa'tube formed of elastic material, la series'of rigid rings fitted to said tubein adjacent end-to- .en'd relation-with each other'along the lengththereof, said rings-in said series being alternately positioned internally andlexternally of said-tbewith the intermediatesections of sai'dtube alone-providingconnections therebetween whicliare universally flexible, the rin-gs disposed internally ofsai'd tube each havinganumber of pairs of `diametrically opposedo'penings'y extending longitudinally through 'the sidewalls thereof, said openings in each internally Vdisposed ring1being`aligned lwith corresponding openings preceding Aand-succeeding similar rings, a like number of 4pairs-of cables'rextending respectively through said pairs ofgraligned openings in eachl of saidalternate* rings,

Vand rnezansadjacent onee-ndl of. said structure for preventing withdrawalofssaid cables in a'direction toward the oppm'siteeiid lof said -struc'ture so that universal iiexing ofsaidstructure can befe'lfected by diterentiallyvarying -thetension oft the cables of each 'pair'thereof '2. A flexible Vtubular structure of the'character described comprising'a Vtube of elastic material, a series of rigid yring-like members fitted to ,said tube in adjacent end-to-end Vrelation with each other along the length thereof, a' first set of said members being positioned internally of said tube, .a' second rset of said membersbeing positioned externally on said tube alternately between respective members of said first set with sections of said tube extending between successive internally and externally disposed ring-like members alone providing connections between said members which are universally fiexible, each of said first set of members having at least one pair of diametrically opposed openings extending longitudinally through the side walls thereof, said openings being aligned with corresponding openings in preceding and succeeding similar members, a pair of cables extending through respective aligned openings in said first set of members, one end of each of said cables being secured to a ringlike member adjacent one end of said structure and opposite ends of said cables being accessible at the opposite end of said structure for manipulation to effect flexing of said structure.

3. A fiexible tubular structure of the character described comprising a continuous tube of elastic material having a substantially uniform wall thickness, a first set of rigid ring-like members having substantially identical outer diameters larger than the normal relaxed inner diameter of said tube, the ring-like members of said first set thereof being positioned internally of said tube in spaced end-toend relation with each other with said tube being expanded in portions thereover, a second set of rigid ring-like members having substantially identical outer diameters approximately equal to the outer diametral size of expanded portions of said tube, said second set of members being positioned externally on said tube alternately between respective members of said first set and in adjacently spaced end-to-end relation therewith, sections of said tube in corresponding spaces between successive internally and externally disposed ring-like members alone providing connections between said members which are universally fiexible, each member of said first set having a number of pairs of diametrically opposed openings extending longitudinally through the side Walls thereof, corresponding openings in members of said first set being substantially axially aligned with each other, a like number of pairs of cables extending through said aligned openings, means securing one end of said cables to one of said members adjacent the distal end of said structure and opposite ends of said cables being accessible adjacent the proximal end of said structure for manipulation thereof to effect lateral flexing of said structure in sections thereof between said ring-like members.

4. A fiexible tubular structure of the character described having proximal and distal opposite ends comprising a continuous tube of elastic material, a series of rigid ring-like members carried by said tube in adjacent endto-end relation with each other, a first set of said members being positioned internally of said tube, a second set'of said members being positioned externally on said tube alternately between and in adjacently spaced end-to-end relation with respective members of said first set, portions of said tube extending between successive ring-like members alone providing connections between said members which are universally flexible, each member of said first set thereof having two pairs of diametrically opposed openings extending longitudinally therethrough and aligned with corresponding openings in preceding members, a first pair of cables extending through one pair of said openings in at least some of said first set of members, a second pair of cables extending through the other pair of openings in at least some of said first set of members, the cables of one pair each having an end thereof connected to a selected ring-like member remote from the proximal end of said tubular structure, the cables of the other pair each having an end thereof connected to a selected ring-like member remote from the proximal end of said tubular structure and the opposite ends of all such cables being accessible adjacent the proximal end of said tubular structure for manipulation thereof to effect selective exing of the structure.

References Cited in the file of this patent UNITED STATES PATENTS 3,006,662 Katsuhara Oct. 31, 1961 3,060,972 Sheldon Oct. 30, 1962 3,071,161 Ulrich Jan. 1, 1963 

1. A FLEXIBLE TUBULAR STRUCTURE OF THE CHARACTER DESCRIBED COMPRISING A TUBE FORMED OF ELASTIC MATERIAL, A SERIES OF RIGID RINGS FITTED TO SAID TUBE IN ADJACENT END-TOEND RELATION WITH EACH OTHER ALONG THE LENGTH THEREOF, SAID RINGS IN SAID SERIES BEING ALTERNATELY POSITIONED INTERNALLY AND EXTERNALLY OF SAID TUBE WITH THE INTERMEDIATE SECTIONS OF SAID TUBE ALONE PROVIDING CONNECTIONS THEREBETWEEN WHICH ARE UNIVERSALLY FLEXIBLE, THE RINGS DISPOSED INTERNALLY OF SAID TUBE EACH HAVING A NUMBER OF PAIRS OF DIAMETRICALLY OPPOSED OPENINGS EXTENDING LONGITUDINALLY THROUGH THE SIDE WALLS THEREOF, SAID OPENING IN EACH INTERNALLY DISPOSED RING BEING ALIGNED WITH CORRESPONDING OPENINGS IN PRECEDING AND SUCCEEDING SIMILAR RINGS, A LIKE NUMBER OF PAIRS OF CABLES EXTENDING RESPECTIVELY THROUGH SAID PAIRS OF ALIGNED OPENINGS IN EACH OF SAID ALTERNATE RINGS, AND MEANS ADJACENT ONE END OF SAID STRUCTURE FOR PREVENTING WITHDRAWAL OF SAID CABLES IN A DIRECTION TOWARD THE OPPOSITE END OF SAID STRUCTURE SO THAT UNIVERSAL FLEXING OF SAID STRUCTURE CAN BE EFFECTED BY DIFFERENTIALLY VARYING THE TENSION OF THE CABLES OF EACH PAIR THEREOF. 